Jialin Qiao created IOTDB-587:
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Summary: TsFile version 2
Key: IOTDB-587
URL: https://issues.apache.org/jira/browse/IOTDB-587
Project: Apache IoTDB
Issue Type: Improvement
Components: Core/Engine, Core/TsFile
Reporter: Jialin Qiao
Fix For: 0.10.0-SNAPSHOT
This issue it to record the TsFile version 2.
In TsFile version 1 (rel/0.9), the ChunkMetadata is stored by device. If we
want to query one series, we need to read ChunkMetadatas of all measurements of
its device, which is time-consuming.
Therefore, we want to avoid this unnecessary cost. The solution is decreasing
the granularity of ChunkMetadata from device to each series.
In the new version, the ChunkMetadata is grouped by each time series. If we
want to query one series, we only need to read ChunkMetadata of this series. A
file level statistics TimeseriesMetadata is added for each series to accelerate
aggregations.
Besides, by modifying the schema management of TsFile, the constraints that
measurements that have the same name in one storage group should have the same
data type is removed.
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